Abstract:
Railway tracks consist of various components and experience different support conditions along the
longitudinal axis. The vertical stiffness of railway tracks varies significantly in space and time, and the
resilient properties of the supporting layers are also affected by several factors. While many studies
propose complex behaviour models for geomaterials to represent these variations, very little work has
been done to account for the random variability of these properties over space and time. In this study,
133-m long 3D train-track numerical models were used to investigate different scenarios with stochastic
spatial variability in the ballast layer. The used finite element method program – Pegasus – considered the
dynamic interaction between the vehicle and the track-substructure system to analyse the influence of the
variability of resilient properties of the ballast layer on the structural response in the time-domain.
Parametric studies are presented studying the influence of speed on the variation of resilient properties in
the ballast layer, and the attenuation of resonance effects was also investigated by evaluating the
differences between models with and without the variability of these properties. The simulations showed
that the variability of resilient properties is expected to have little influence on the overall response of the
vehicle-track-soil system. However, the analysis of mean and deviatoric stresses suggested that it may
have some relevance in terms of the local stress analysis in the ballast layer.